Water insoluble disazo-dyestuffs



United States Patent WATER INSOLUBLE DISAZO-DYESTUFFS Hans WilhelmLiechfi, Oberwil, Basel-Land, Switzerland, assignor to Ciba Limited,Basel, Switzerland, a firm of Switzerland No Drawing. Filed Jan. 2,1959, Ser. No. 784,461 Claims priority, application Switzerland Feb. 12,1958 7 Claims. (Cl. 260-486) The present invention provides newdisazo-dyestufls which are free from groups imparting solubility inwater and correspond to the general formula in which A represents abenzene radical which has a nitro group in ontho position or preferablyin meta-position to the azo linkage, B represents a benzene radical andC represents a benzene radical containing a hydroxyl group inpara-position to the azo linkage.

The new disazo-dyes-tufis of this invention are obtained by coupling ahvdroxy-benzene capable of coupling in Amino-.azo-dyestuds of the aboveFormula 2 may be prepared by coupling a diazo-compound of an orthoor'meta-nitraniline, for example, l-amino-Z-nitrobenzene,l-amino-B-nitrobenzene, laamino-2-nitro-4-methylbenzene orl-amino-Z-nitro-methoxybenzene with an aminobenzene which is tree fromgroups imparting solubility in water as the middle component and whichcapable of coupling in para position relatively to the amino group,

for example, aniline, 2-chloraniline, 2- or B-methoxy-aniline, 2- or3-ethoxy-aniline, 2:5-dimethoxy-aniline, 2:5- diethoxy aniline, 2- or3-methyl-aniline, 2:5-'dimethylaniline, 2-methoxy-5-me'thyl-aniline or2-chloro 5-methoxy-aniline, The coupling is advantageously carried outin a medium ranging from weakly acid to weakly alkaline, for. example, amedium rendered acid with acetic acid or alkaline with an alkali metalbicarbonate. If the middle component has a low coupling power, it isusually preferable to couple it in the form of its w-methanesuifonicacid, the w-methane sultonicacid group is subsequently split off. is thecase, for example, with l-amino-Z-methoxy-benzene. The diazotization ofthe amino-azo-dyestufis of the above formula can be carried out in knownmanner, for example, by means of hydrochloric acid and sodium nitrite.In the process of this invention, the diazo-aminocompound so obtained iscoupled with the end component in :an' alkaline medium, for example, onerendered alkaline with an alkali metal carbonate, and advantageously inthe presence of an added coupling assistant such, for example, aspyridine or a picoline.

Sui-table as end components are those hydroxybenzenes which are capableof coupling in para-position relatively to their hydroxvl group, such,for example, as phenol, 1 hydroxy-Z-methyl-benzene, 1-hydroxy-3-methylbenzene, 1-hydroxy-3-methoxy-benzene, l-hydroxy-Z-chlorobenzene,2:5-dimethyl-phenol or 3:5-dimethyl-pheno1. Instead of a singlehydroxy-benzene, a mixture of two or more hydroxy-benzenes, for example,a mixture of two isomeric hydroxy-benzenes can be used.

The new disazo-dyestutfs, especially after they have had an appropriatepasting treatment which may be combined with reprecipitation, torexample, irom acid, are very suitable for dyeing or printing shapedstructures, especially polyester fibrous materials such, tor example, asthose of polyethylene terephthalates, which are known.- under theregistered trademarks of Terylene and Dacron. By dyeing by the usualmethods, :for example, in a dyebath containing a dis ersion of thedyestulf and advantageously also containing 'a dispersing agent, and ata temperature close to C., and if desired with the addition of aswelling agent, or at a temperature above 100C. under superatmosphericpressure there are'obtained pure and generally full orange to scarletdyeings of very good fastness to light and sublimation. The newdyestuifs may also be used for dyeing or printing shaped structures ofesters or ethers of cellulose, super-polyamides or super-polyurethanesor of polyvinyl chloride. They may also be used as pigments.

The following examples illustrate the invention, the

par-ts and percentages being by weight:

Example 1 28.6 parts of 4-an1ino-2-methyl-S-methoxy-3' nitrol:1'-a'zo-benzenewere dia'zotized in known manner the solution of thediazo compound was filtered throughactive carbon. The filtrate wascoupled at a temperature Within the range of 5 C,l0 C with a solution of9.4 parts of hydroxybenzene in 100 parts of Vii-31613.10 parts of a 30%solution of sodium hydroxide, 20 parts of sodium carbon-ate and 20 partsof sodium acetate. Coppling took place nnmediately. The product wasfiltered an, washed neutral with water and dried.

Thewater-insoluble dyestu'ff was obtained as a brown powder, which wasused in a fine dispersion to dye rayon and polyamide fibers, such :asnylon and perlon, and gave an orange tint of excellent fastness. Above:all, the new dy stufi, dyed polyester fibers, such as Dacron, Teryleneor "Diolen (regd. trademarks) full orange tints of outstanding Iastnessto sublimation. 7

A dyestufr" having similar properties as that obtained above, wasobtained when 4 amino-2-methyl-5-methoxy- 2- nitro'-l;l' -azobenzene wasused as starting material instead of 4'-amino-2methyl-5-methoxy-3'nitroel z'l' azobenzene.

When 4-amino-2:5-dimethyl-3'-nitro-1:1 azobenzene was used as startingmaterial instead of either of those mentioned above, a dispersiondyestufi was obtained which dyed the above mentioned materials yellowishorange tints having the same good properties as had the other dyestufis.

Example 2 28.6 parts of 4-amino-Z-methyl-5-methoxy-3'-nitro-1:1-azobenzene were diazotized in known manner and the solution of thediazo compound was filtered through active carbon. The filtrate, at atemperature the range of 5 0-10" C. was added to a solution of 10.8parts of l-methyl-Z-hydroxy-benzene in 100 parts of water, 10 parts of a30% solution of soduim hydroxide, 20 parts of sodium carbonate and 10parts of sodium acetate. The product was filtered ofi, washed neutralwith water and dried.

The water-insoluble dyestufi was obtained as a brown powder which wasused in a fine dispersion to color rayon and polyamide fibers, such asnylon and perlon, and gave an orange tint of excellent fastness. Aboveall, the new dyestufif colored polyester fibers such as Dacron,Terylene, or Diolen (registered trademarks) full orange l 7 Example 3 .1part of the dyestutf obtained in Example 1 was milled wet with 2 partsof a 50% aqueous solution of cellulose sulfite lye and then dried.

The dyestuif preparation thus obtained was stirred wit 40 parts ofaaqueous solution of a condensation product of octodecyl alcohol and 20molecular proportions of ethylene oxide, and to this were added 4 partsof a 40% acetic acid solution. After diluting with water v4000 parts ofa dyebath were obtained.

100 parts of a cleaned polyester fiber material was placed into theabove bath at 50 C., the bath was then heated in half an hour to atemperature within the range of 120 C. to 130 C. and dyeing was carriedout for 1 hour in the closed vessel at that temperature. The materialwas then well rinsed. The resulting dyeing was full bright orange ofvery good fastness to light and sublimation. When the above-mentioneddye bath contained 8 parts of soap instead of the 4'parts of 40% aceticacid solution, a dyeing was obtained which has similar properties ofstrength, coloration and fastness.

Example 4 r 100 parts of a cleaned polyester fibrous material weretreated for minutes in a dyebath at 50 C. containing, per 4000 parts, 12parts of diammonium phosphate vwith 400 parts of a 10% aqueous solutionof a condensation product from octadecyl alcohol and molecularproportions of ethylene oxide.

To the above bath was added 1 part of a fine dispersion of the dyestuifobtained in Example 1 in 2 parts of a 50% aqueous solution of cellulosesulfite lye, and the bath temperature was then raised in half an hour tothe boil. Dyeing was carried out for 1 hours to 2 hours at the boil.

- The dyed material was then placed in a bath containing 2 parts of asodium hydroxide solution and 10 parts of a 10% aqueous solution of acondensation product from octadecyl alcohol and 20 molecular proportionsof ethylene oxide, per 1000 parts of water, and treated therein for 30minutes at 70 C. and then rinsed. A full bright orange dyeing wasobtained of good fast- -ness to light and very good fastness tosublimation, and

which corresponded exactly in strength and tint to that obtained inExample 3.

4 What is claimed is: 1. A disazo-dyestuif which corresponds to theformula A-N=N-BN=NC-OH No. on.

4. The disazo-dyestufi of the formula N O 2 C Ha 5. The disazo-dyestufiof the formula A CH3 N O a 0 H3 7 6. Thedisazo-dyestuif of the formula7. The disazo-dyestufi of the formula 0 CHa i No, CH3 0113 ReferencesCited in the file of this patent UNITED STATES PATENTS 2,782,185 MerianFeb. 19, 1957

1. A DISAZO-DYESTUFF WHICH CORRESPONDS TO THE FORMULA